libvirt users - Mar 2016 - [help] How to modify the vgamem value ?

Dear everyone 
       Do you know how to modify  vgamem value in the .xml file ?  such as
:<video>
      <model type='qxl' ram='65536' vram='65536'
vgamem='16384' heads='1'/> // from  instance-0000015e.xml
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x02' function='0x0'/</video>
I plan to increase the  volume of vgamem , but  it seems that always keep the
original value ‘16384’. Was it limited by QEMU? or others？  Please tell me how I
can I modify it ? it's better that help me to make a example for modifing
the vgamem.....

Thank you very much 
Best Regards .

Hi Luo,

the vgamem is limited inside. Myself, I use QEMU 2.5/Virgil3D to expand
the vgamem.

May be someone have a better solution or an example to solve it.

Best regards,

Holger

================================================================
example:

<domain type='kvm'
xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>

.
.
<!-- Begin device declaration -->
  <devices>
.
.
  <!-- Videocard -->
      <video>
        <model type='virtio' heads='1'/>
          <alias name='video0'/>
          <address type='pci' domain='0x0000'
bus='0x00' slot='0x0b'
function='0x0'/>
      </video>

.
.
.
<!-- End device declaration -->
  </devices>

  <qemu:commandline>
.
.
    <qemu:arg value='-global'/>
    <qemu:arg value='VGA.vgamem_mb=128'/>    <--- here is the
size
    <qemu:arg value='-set'/>
    <qemu:arg value='device.video0.driver=virtio-vga'/>
  </qemu:commandline>

================================================================


Am 14.03.2016 um 09:20 schrieb hongzhen_luo@sina.com:
> Dear everyone
> 
>        Do you know how to modify  vgamem value in the .xml file ?  such as
:
> 
> <video>
>       <model type='qxl' ram='65536' vram='65536'
vgamem='16384'
> heads='1'/> // from  instance-0000015e.xml
> 
>       <address type='pci' domain='0x0000'
bus='0x00' slot='0x02'
> function='0x0'/
> 
> </video>
> 
> I plan to increase the  volume of vgamem , but  it seems that always
> keep the original value ‘16384’. Was it limited by QEMU? or others？ 
> Please tell me how I can I modify it ? it's better that help me to make
> a example for modifing the vgamem..... 
> 
> 
> Thank you very much
> 
> Best Regards .
> 
> 
> 
> 
> 
> _______________________________________________
> libvirt-users mailing list
> libvirt-users@redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users
>

On Mon, Mar 14, 2016 at 09:41:36AM +0100, Holger Schranz
wrote:
> Hi Luo,
> 
> the vgamem is limited inside. Myself, I use QEMU 2.5/Virgil3D to expand
> the vgamem.
It's not limited and can be modified inside the xml, the only limitation is
that
the value has to be a power of 2 and for QXL the value must be at least 1024.
There is an exception, qemu can and in some cases updates the value internally,
libvirt after the guest is started will get the actual value from qemu and
update live XML.

Pavel